/**
 * The contents of this file are subject to the OpenMRS Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://license.openmrs.org
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
 * License for the specific language governing rights and limitations
 * under the License.
 *
 * Copyright (C) OpenMRS, LLC.  All Rights Reserved.
 */
package org.openmrs.module.datalogging.web.controller;

import java.io.OutputStream;
import java.util.Collection;
import java.util.HashSet;
import java.util.Set;

import javax.servlet.http.HttpServletResponse;

import org.apache.commons.beanutils.BeanUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.codehaus.jackson.JsonEncoding;
import org.codehaus.jackson.JsonFactory;
import org.codehaus.jackson.JsonGenerator;
import org.openmrs.api.context.Context;
import org.openmrs.module.datalogging.filter.Filter;
import org.openmrs.module.datalogging.filter.FilterFactory;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;

/**
 *
 */
@Controller
@RequestMapping("/module/datalogging/filterFinder")
public class FilterFinderController {
	
	/** Logger for this class and subclasses */
	private static final Log log = LogFactory.getLog(FilterFinderController.class);
	
	@RequestMapping(method = RequestMethod.GET)
	public void findFilter(@RequestParam("searchTerm") String searchTerm, @RequestParam("filterName") String filterName,
	                       HttpServletResponse response) throws Exception {
		if (Context.isAuthenticated()) {

			response.setContentType("application/json");
			
			Filter filterHandler = FilterFactory.getHandler(filterName);
			Object object = filterHandler.getFilterValues(searchTerm);
			if (object instanceof Collection<?>) {
				Collection<?> variables = (Collection<?>) object;
				Set<Object> set = new HashSet<Object>(variables);
				
				if (log.isDebugEnabled())
					log.debug("Found: " + set.size() + " unique filtering object ...");
				
				OutputStream stream = response.getOutputStream();
				
				JsonFactory f = new JsonFactory();
				JsonGenerator g = f.createJsonGenerator(stream, JsonEncoding.UTF8);
				g.useDefaultPrettyPrinter();
				
				g.writeStartObject();
				g.writeArrayFieldStart("elements");
				
				for (Object o : set) {
					g.writeStartObject();
					String id = BeanUtils.getProperty(o, "id");
					g.writeStringField("id", id);
					String name = BeanUtils.getProperty(o, "name");
					g.writeStringField("name", name);
					String description = BeanUtils.getProperty(o, "description");
					g.writeStringField("description", description);
					g.writeEndObject();
				}
				g.writeEndArray();
				g.writeEndObject();
				
				g.close();
			}
		}
	}
}
